This invention relates to new and useful improvements in clean out devices for conduits and is an improvement over the structure shown in Canadian Pat. No. 862555 and U.S. Pat. No. 3,724,505.
These patents illustrate and describe a clean out device consisting of a substantially oval frame which is welded into position around an aperture cut within a pipe or conduit and has a detachable cover plate engaging a valve seat on the underside of the frame and is clamped into position upwardly against the frame so that pressure within the pipeline or conduit, accentuates rather than reduces, the sealing relationship between the cover and the frame.
There are disadvantages inherent in the original or conventional clean out device such as the difficulty or sometimes impossibility to remove the cover downwardly from the frame particularly when a plug-up occurred directly under the cover or if the cover becomes corroded or rusted to the periphery of the frame as often happens, particularly after extended use.